This invention relates generally to pool cleaning systems of the type including a so-called automatic pool cleaning device adapted for travel over submerged surfaces of a swimming pool or the like to pick up and collect accumulated debris such as leaves, twigs, sand and silt. More particularly, this invention relates to a flow controller for installation along a flexible hose or the like used for connecting the pool cleaner to a hydraulic power source such as a suction or vacuum source by connection to the suction side of a conventional pool water filtration system. The flow controller of the present invention is designed to maintain the suction pressure applied to the pool cleaner at a substantially constant and easily adjustable preset threshold level consistent with substantially optimized pool cleaner operation.
Pool cleaner systems and related devices are generally well known in the art for use in maintaining residential and commercial swimming pools in a clean and attractive condition. In this regard, swimming pools conventionally include a water filtration system equipped with a pump for drawing or suctioning water from the pool for circulation through a filter canister having filter media therein to remove and collect water-entrained debris such as leaves and twigs as well as fine particulate including sand and silt. In a typical arrangement, at least a portion of the pool water is vacuum-drawn over a weir mounted within a so-called skimmer well positioned substantially at the water surface to draw and collect floating debris to the filter equipment. From the filter canister, the water is recirculated to the pool via one or more return lines. Such filtration equipment is normally operated for several hours on a daily basis and serves, in combination with traditional chemical treatments such as chlorination or the like, to maintain the pool water in a clean and clear sanitary state. However, the water filtration system is ineffective to filter out debris which settles onto submerged floor and side wall surfaces of the swimming pool. In the past, settled debris has typically been removed by coupling a vacuum hose to the suction side of the pool water filtration system, such as by connecting the vacuum hose to the skimmer well located near the water surface at one side of the pool, and then manually moving a vacuum head coupled to the hose over the submerged pool surfaces to vacuum settled debris directly to the filter canister where it is collected and separated from the pool water. However, manual vacuuming of a swimming pool is a labor intensive task and is thus not typically performed by the pool owner or pool cleaning service personnel on a daily basis.
So-called automatic pool cleaner devices have been developed over the years for cleaning submerged pool surfaces, thereby substantially eliminating the need for labor intensive manual vacuuming. Such automatic pool cleaners typically comprise a relatively compact cleaner housing or head coupled to the pool water filtration system by a hose and including water-powered means for causing the cleaner to travel about within a swimming pool to dislodge and collect settled debris. In one form, the pool cleaner is connected to the return or pressure side of the filtration system for receiving positive pressure water which powers a turbine for rotatably driving cleaner wheels, and also functions by venturi action to draw settled debris into a filter bag. See, for example, U.S. Pat. Nos. 3,882,574; 4,558,479; 4,589,986; and 4,734,954. In another form, the pool cleaner is coupled by a vacuum hose to the suction side of the filtration system, whereby water is drawn through the pool cleaner to operate a drive mechanism for transporting the cleaner within the pool while vacuuming settled debris to the filter canister of the pool filtration system. See, for example, U.S. Pat. Nos. 3,803,658; 4,023,227; 4,133,068; 4,208,752; 4,643,217; 4,679,867; 4,729,406; 4,761,848; 5,105,496; 5,265,297; 5,634,229; and 6,094,764. See also copending U.S. Ser. No. 09/176,532, filed Oct. 21, 1998.
For optimum cleaning efficiency, it is normally desirable to provide a substantial and relatively constant water pressure for operating the pool cleaner to achieve traversal of submerged pool floor and side wall surfaces with sufficient traction to maintain vacuuming structures in close proximity with the submerged pool surfaces, and also to insure pool cleaner travel in a substantially random pattern while covering of most or all submerged pool surfaces within a relatively short period of time. However, the available pressure generated by the pool water filtration system can vary widely in accordance with numerous factors, such as differences in pump size and power, pipe line sizes, filter canister capacity and degree of cleanliness, etc. For this reason, pool cleaners have typically been designed for substantially optimized operation at a water pressure somewhat less that the maximum pressure capacity of a typical filtration system, and a flow regulator or controller is normally provided to limit the pressure coupled to the pool cleaner to a selected design threshold consistent with proper cleaner performance. See, for example, U.S. Pat. Nos. 5,363,877; 5,033,504; 5,570,713; 4,729,406; 4,643,217; 5,285,547; 5,477,879; 5,363,878; 5,351,709; 5,105,848; 4,790,344; 4,570,660; 4,368,751; and 4,683,599 for a variety of flow controller devices designed for limiting the suction pressure applied to a suction powered pool cleaner by modulated opening of a bypass relief port. These flow controller devices additionally and beneficially insure an uninterrupted supply of water to the suction side of the pool filtration pump in the event that the associated suction powered pool cleaner becomes clogged. However, these prior devices generally do not accommodate quick and easy adjustable setting of the suction pressure limit, as is frequently desired for fine-tuning the specific operating characteristics of a pool cleaner in accordance with the geometric configuration of a particular swimming pool.
The present invention relates to an improved flow controller for regulating and maintaining the water pressure coupled to a pool cleaner at a selected threshold limit consistent with substantially optimized pool cleaner operation, wherein the pressure threshold is quickly and easily adjustable for fine-tuning the specific operating characteristics of the pool cleaner.